Automatic painting machine



June 19, 1962 R. B. WAY ETAL 3,039,431

AUTOMATIC PAINTING MACHINE Filed May 1, 1958 4 Sheets-Sheet 1 6 us I I20 I9 II 6 120 I 106 o x I) z T INVENTORS ROBERT B. WHY CARL D. HERSEY24A A/mu @Zwr June 19, 1962 R. 5. WAY ETAL AUTOMATIC PAINTING MACHINEFiled May 1, 1958 4 Sheets-Sheet 2 INVENTORS ROBERT B. WAY CARL D.HERSEY June 19, 1962 R. B. WAY ETAL 3,039,431

AUTOMATIC PAINTING MACHINE Filed May 1, 1958 4 Sheets-Sheet 3 F/a, 5INVENTORSY ROBER B. \A/FIY CHRL D. HERSEY F/a 6 BY J1me 1962 R. B. WAYETAL AUTOMATIC PAINTING MACHINE 4 Sheets-Sheet 4 Filed May 1, 1958 SY on ws m A W T n OR RC Y B iinited States This invention relates toprocessing machines and, more particularly, to machines forautomatically painting articles of manufacture wherein the processingtool or paint gun and the work move relative to each other in a parallelpath.

The machine described herein has especial utility in thefield ofautomatically painting predetermined areas on articles of manufacturesuch as plastic parts and the like.

In previous machines, particularly painting machines, for paintingarticles of manufacture wherein the paint applying means and the workmoved relative to each other, these machines had the disadvantage thatthe relative movement of the work and the paint applying means was notconstant and where mechanisms were provided for making the said relativemovement constant, the mechanisms were complicated and not compact inarrangement. In many cases, the relative movement between the work andthe tool was not smooth and, therefore, the coating material was notapplied to the articles of manufacture in a smooth even manner. Further,on previous machines of this type, it was difficult to mount the coatingapplying means in such a way that the coating could be applied in thedesired manner to the work and the tools could not generally be spacedlaterally a sufficient distance from each other.

In the machine disclosed herein, by using the rotomation motor, thechain drives achieve a very smooth travel of the guns due to the factthat hydraulic oil is used in the driving means. The speed of thecarriage is entirely constant; that is, there is no change in thevelocity of the carriage as there would be when a crank and a lever armare used for driving a reciprocating mechanism and a variable stroke isused on the carriage. Valves are mounted together on a movable bracketwhich can be moved clockwise around the cam, thus shortening the lengthof stroke. The stroke then can be cut down to almost six or eight inchesif there is a short part to be painted.

The crankshaft on which the guns are mounted is fashioned in such a waythat it can hold one, two, or up to as many as four spray guns. It canspray one color out of one pair of guns and another color out of theother pair.

Another feature of the machine is the adjustable fixture which holds thepart for painting. This fixture can be positioned in such a manner thatthe part can be held under the center ofthe carriage or it can be heldto the front or the back of the carriage. A gun cannot be mounteddirectly in the middle of the carriage but, by moving the fixture, thepart can be placed directly under a gun which sits on the front of thecrank of the crankshaft and, therefore, it is possible to paint straightdown on the machine. The length of the cam shaft permits mounting of theguns spraying down at angles so that complete coverage of the part isaccomplished. The tilting of the guns, of course, permits paintingaround bridges and into corners and otherwise inaccessible places andthe mounting of the guns spraying in from the side also helps in thatway. A depressed part or a raised part can be painted and very goodcoverage can be obtained because the spread of the guns on thecrankshaft is also aided by the bend of the tilting mechanism. Someprevious machines of this description have utilized a hydraulic cylinderwhich extended beyond the side of the atent machine because of itsextreme length. The machine will be twice as long as the cylinder.

More specifically, it is an object of this invention to provide amachine which will accomplish the purposes set forth herein and, moreparticularly, it is an object to provide a machine which is simple inconstruction, economical to manufacture, and simple and efiicient inoperation.

Another object of the invention is to provide a machine for the purposeset forth wherein the work and the processing tool move relative to eachother in a longitudinal path, the movement being smooth and constant.

Still another object of this invention is to provide an improved fixturein combination with an automatic painting machine.

A further object of the invention is to provide an improved means forsupporting a paint gun on an automatic painting machine.

Yet a further object of the invention is to provide an improvedautomatic painting machine.

With the above and other objects in view, the present invention consistsof the combination and arrangement of parts hereinafter more fullydescribed, illustrated in the accompanying drawings and moreparticularly pointed out in the append claims, it being understood thatchanges may be made in the form, size, proportions, and minor details ofconstruction without departing from the spirit or sacrificing any of theadvantages of the invention.

In the drawings:

FIG. 1 is an isometric view of the machine disclosed herein to a reducedscale;

FIG. 2 is a partial view of the overhead operating mechanism for themachine with certain parts omitted;

FIG. 3 is a top view of the driving mechanism shown in FIG. 2 withcertain parts omitted;

PEG. 4 is an end view of the mechanism shown in FIGS. 2 and 3 withcertain parts omitted;

FIG. 5 is a partial view of the gun tilting mechanism according to theinvention;

FIG. 6 is a side view of the mechanism shown in FIG. 5; and

FIG. 7 is a piping diagram of the machine according to the invention.

Now with more specific reference to the drawings, the machine is made upof a frame having four spaced legs 1tl1 which support a top frame member102. On the top frame member 102 is supported an overhead reciprocatingmechanism 193 which includes a rotomation motor 1% and a gun carriage113 having a gun tilting mechanism 83 thereon. The motor 104 has amounting plate 1% fixed thereto and has a slot .115 formed therein. Theslot 115 receives a sliding bracket 112 which supports valves 18 and 23.The rotomation motor can be constructed like the motor shown in PatentNo. 2,793,623 or Patent No. 2,798,462.

The valves 18 and 23 are connected together so that they slide in unisonwith the sliding bracket 112. Valves 17 and 28 are fixedly attached tothe plate 105. A handle 117 extends through the bracket 112 and throughthe slot 115 and is threaded into a nut plate \124. When the handle 117is rotated to loosen it in the nut plate 124, the bracket 112 may beslid along the slot 115 in the mounting plate 105, thus adjusting theposition of the valves 18 and 23 and thereby adjusting the stroke of thegun carriage r113.

Cover members 106 may constitute the top of a table and the covermembers 106 are flat on top and supported on laterally disposed channelmembers 157 and 108 which have angle members 109 attached to the lowerends thereof. Tracks in the form of longitudinally disposed rods 110extent through holes in the vertical flange of the angle members 109 andhave nuts 111 thereon which secure the rods 11% in place whereby theyare supported.

The gun carriage 113 is made up of two blocks 135 and 133 held togetherby two I-frame members 116 which are connected by a plate 134%. Boresthrough the blocks 135 and 133 receive the track rods 110 and slidethereon. A plate 114 is attached to the inner side of the block 133. Acylinder 21 is attached to the front end of the plate 114 by means ofscrews 136 and a cylinder 22 is attached to the other end of the plate11-1 by means of screws 137.

A longitudinally extending plate 137 is attached to the lower side ofeach block 133 and 135 and to each plate 137 is attached one of thepillow blocks 138. An intermediate bearing 139 of a crank 85 isjournalled in the pillow blocks 133 and crank arms 14% and 141 supportgun supporting arms 142 and 143. An intermediate block 83 is clamped tothe intermediate bearing 13-9 by a bolt 144. A block 83 has an arm 145attached thereto and the arm l ihas a vertical slot 146 therein.

The piston rods of the pistons in the cylinders 21 and 22 are integrallyattached together and a laterally extending pin 1 17 is fixed to a rod77 and extends radially therefrom and is received in the slot 146 in thearm 1 45. Since the bearing 139 is journalled in the blocks 133, itcannot move but can only rotate and as the piston rod 77 moves from sideto side, the arm 145 rotates the bearing 139 and swings the arms 14-2and 14-3.

The top plate 130 is attached to plates 11?; which are attached to achain 119. The chain 119 passes around sprockets 120 and 121 and arounda sprocket 122 which is attached to a shaft 123 of the rotomation motor104. The sprockets 120 and 121 are supported on shafts 151} and 151which are journalled in pillow block bearings 123 which are, in turn,fixed to the cover members 1% of the frame 101 As the rotornation motor1% rotates, its sprocket 122 rotates with it and this drives the chain119, thereby causing the carriage 113 to traverse on the rod tracks 119.The plates 118 are held in place by screws 14 9 and may be moved toadjust the tension of the chain 119. The rotomation motor 104 isconstructed such that when oil is forced therethrough in one direction,the motor 104 rotates in a first direction and when the oil is forcedthrough it in a second direction, the motor 104 rotates in the oppositedirection. Therefore, when oil is forced through the motor 1114 in onedirection, it will move the gun carriage i113 to the right and when theoil flow is reversed, it will move the gun carriage 11.3 to the left.

A rest pad 129 is attached to the upper end of a square piston rod 126for supporting a part 131 to be painted. The piston rod 126 is square incross section to prevent it from rotating during its upward and downwardtravel.

A mask 132 is generally rectangular in shape and its ends are receivedin slots 134 in rods 148. The rods 14% are fixed to support members 152which are in turn fixed to base plates 153 in turn fixed to a plate 154.The plate 154 is fixed to a lower frame member 15%. The lower framemembers 159 are fixed to the legs 10 1.

When air is applied in a cylinder 125 below a piston 127, the piston rod126 will raise the rest pad 129 and the part 131 to bring the part 131into a concavity located in the central portion of the mask 132. Thesaid concavity will be in the form of a counterpart of the surface ofthe part to be painted with openings therethrough to allow paint fromguns 162 to be deposited on the exposed areas of the part. The mask 132is of the type in general use with automatic painting machinery.

Air and Hydraulic Circuit The air and hydraulic circuit is shown in FIG.7 and shows a cam 16 which is attached to the shaft 123 of therotomation motor 104. The oil circuit for the rotomation motor 104 ismade up of pipes 30, 31, and 32 and a pump 33 which is driven at aconstant rate of speed. The flow of oil through the pipes 30, 31, and 32is controlled by valves 14 and 25 as well as restricting check valves 35and 36 which each allow oil to flow freely in one direction but checkthe flow thereof in the other direction and meter the flow, thereby checing the movement of the motor 194. The pump 33 is supplied fluid from asump 39 and the pump 33 discharges fiuid through the valves 25 and 14 tothe rotomation motor 1114.

Air is supplied through a line 4-6 at a suitable pressure and it flowsthrough a filter 41 and to a pipe 42. From the pipe 42, it flows througha pressure regulator 13 to a line 4 1 at a predetermined pressure to theatomizing air supply on the guns 162. This pressure may he observed on agauge 45. Air from the filter 41 further passes through a lubricator 53into a line 54 which is the main air supply line to the machine.

Air from the pipe 42 is also connected to the main air passage of astarting valve 46 which is a manually controlled valve having a manualcontrol 47 thereon which may be operated either by the hand or by thefoot of an operator and which controls the flow of air either to acontrol line 48 and thence to a cut-out valve 4% or to a line 511 whichis connected to a pilot control 51 of a valve 26. The line 50 exhauststhrough an exhaust 52 when the manually controlled valve 46 is turnedoff.

Starting the Machine With the machine disclosed herein, the cut-outvalve 49 will pass through so much air and then shut off. There is airgoing through the starting valve 46 through the line 48 to the cut-outvalve 49 and the air cannot pass through the cut-out valve 4-9 until thepressure behind it is discharged and air pressure is again put on it.Therefore, to start the machine, the operator actuates the startingvalve 46 which may be a foot pedal or a hand actuated spring returnfour-way valve. This exhausts the line 48 and exhausts the cut-out valve49. At the same time, air flows from the pipe 42 through the valve 46and the line 50 to the pilot control 51 of the valve 26. The pilotcontrol 51 opens the valve 26, passing air from a regulator 167 and aline 97 through a line 98, check valve 99', the orifice in parallel withvalve 99", and pipe 164 to the cylinder which raises the piston 127,forcing the part 131 to be painted into the mask 132.

When the starting control valve 46 is released, a spring 61 reverses itand it comes back to the position shown. Thus, when the valve 46 isactuated, it allows air to pass first through the line 51} to the pilotcontrol 51 connecting air to a pipe 164 and then through the valve 46,the line 48, through the cut-out valve 49, a line 60, to a double pilotoperated three-way valve 11. This air pressure will be impressed on apilot 12.

No time delay in the air circuit is necessary between the actuation ofthe cylinder 125 and the actuation of the guns 162. The amount of timerequired to press the foot pedal down, let it up, and the machine tostart is enough for the air piston 127 to completely push the part 131into place in the mask 132 before the gun 162 starts to move so there isno positive mechanical linkage necessary to delay the starting of thegun carriage 113. Flow control valve 16 is used to delay the opening ofthe spray guns 162 so as to insure that the guns 162 do not start tospray before the carriage 113 starts to move. Actuating the foot pedalwill raise the air piston 127, pushing the part 131 into the mask 13 2and also exhausting the cut-out valve 49'. When the foot pedal isreleased, the cut-out valve 49 will, of course, pass air to the valve11. The piston 127 does not drop when the foot pedal is released becausethe valve 26 which controls it is a double piloted valve and it remainsopen until it is closed by air from the valve 17 as a cam 16 rotatingclockwise engages it. When air from the valve 17, closes the vlave 26,the air under the piston in cylinder 125 flows back through check valve99', through the orifice in parallel with valve 99, and is exhaustedinto the atmosphere by valve 26. Thus, the piston in cylinder 125descends at a rate controlled by the size of the orifice in parallelwith check valve 99.

The air coming in from the starting valve 46 through the cut-out valve49 will move the control member in the valve 11, opening the valve 11.This puts air pressure in a line 13 and the air flows through the line13 to the left over a pilot 62 of a left hand hydraulic valve 14 andopens the valve 14'. Air from the line 13 also flows to a pilot 63 on athree-way valve 15. When the valve 15 is thus opened, air flowstherethrough from a line 54 through a line 64 and a valve 20 to a line65, a shut-off valve 66, a quick exhaust valve 67 to a line 68, andthence to the spray guns 162. The hydraulic valve 14 which has beenopened by the pilot 62 passes hydraulic fluid from a pipe 32 to a pipe30 and thence to the rotomation motor 104 which starts the cam 16rotating counterclockwise.

The first portion of rotation of the cam 16 to the valve 17 is notefiective on counterclockwise rotation as the valve 17 operates onlywhen the timing cam 16 is rotating clockwise. The valve 18 operates onlywhen the cam 16 is turning counterclockwise and does not operate whenthe cam 16 is rotating clockwise. Therefore, the valve 14, havingopened, will pass oil to the rotomation motor 104 and the cam 16 will berotated counterclockwise. Since the shaft 123' is also connected to thesprocket 122, the gun carriage 113 will move to the right.

This movement will continue past the valve 17 not affected until a camsurface 7 0 strikes an actuating member 71 on the valve 18. This willopen the valve 18, passing air from the valve 18 and the line 54 to aline 72 and a four-way valve 19. This will actuate a member 84 on thevalve 19 and connect air from the line 54 to a line 74 which operatesthe gun tilting mechanism through a flow control valve 56 and thecylinder 21 having a piston 76 therein connected to the piston rod 77.Air also flows from the line 72 to the gun shut-off valve 20 which isclosed, thus shutting off the spray guns 162. The cam surface 70 is justbefore the end of the stroke so that as the gun carriage 113 reaches apoint near the end of its travel toward the right, the piston rod 77will act through a pin 147, the block 83, and a crank 140 to incline theguns 162 and cause them to direct their spray in the other direction.The guns 162 will be shut off just before they start to tilt.

Rotation of Cam 16 (From Valve 18 to Valve 23) The cam 16 continues itsrotation until the surface 70 strikes actuating member 86 on thethree-way valve 23 at the end of the stroke of the cam 16. When thevalve 23 is opened, air is passed from the line 54 to line 87 and thento a pilot 12 of the valve 11, pilot 89 of the valve 24, and pilot 90 ofthe valve 20. The valve 11 is thus closed, exhausting pilot 62 of thevalve 14 and pilot 63 of the valve 15.

Pressure on the pilot 89 of the valve 24 opens the valve 24, passing airfrom line 54 to line 91 to pilot 161 of the valve 25 and the pilot 160of the valve 14. This action closes the valve 14 and opens the valve 25which causes the rotomation motor 104 to reverse its motion to aclockwise rotation. The passage of air to the pilot 90 of the valve 20opens the valve 20, permitting actuating air to flow from the line 54through the valve 15, the line 64, the valve 20, the line 65, theshut-off valve 66, quick exhaust valve 67, and line 68 to the spray guns162, turning them on to spray as the carriage 113 moves to the left.

The valve 25 is opened, the valve 14 is closed, and the motor 104 isreversed and the motor 104 now rotates clockwise, thus moving thecarriage 113 to the left. The guns 162 have been turned on when thevalve 20 is opened and the tilting mechanism is tilted so that the guns162 now spray and are inclined in the opposite direction and the spraywill continue as the cam 16 rotates clockwise past the valve 18 which isnot effected by clockwise rotation of the cam 16. When the cam 16 opensthe valve 17, the air from the line 54 flows therethrough to the line 94to pilots 95 and 96 of the valves 15 and 26. The valve 15 shuts off thespray guns 162 and the threeway valve 26 connects the line 98 to theexhaust port, exhausting line 164 and the air cylinder 125. The pistonrod 126 of the cylinder which has been holding the part being paintedtightly in the mask is thus lowered, dropping the part down out of themask.

The cam 16 continues to rotate past the valve 17 until the surface 70engages member 163 on the valve 28. Air from the line 74 through thevalve 28 flows to pilot of the valve 25 from line 156 and closes thevalve 25, thus stopping the rotomation motor 104. Air from the line 156also actuates pilot 157 on the valve 19. When air is applied to thepilot 157 of the valve 19, it reverses the air flow through the valve19, applying air to line 81 and to the air cylinder 22. This moves thepiston rod 77 to the left and tilts the gun holding mechanism, includingcrank 85. The air in the line 156 also flows to the pilot 158 of thevalve 24 and closes the valve 24.

As the air in the line 74 which passes through the valve 28 is suppliedthrough the valve 19, the valve 28 actually shuts otf its own air supplywhen it opens and allows air to flow to the pilot 157 of the valve 19.Therefore, restrictor 178 has been placed in the exhaust port of thevalve 19 so that sufficient pressure will be momentarily retained in thelines 74 and 156 to ensure the actuation of the pilots 158, 155, and157.

Valve 180 is installed in the circuit as a safety feature. It is amanually operated valve having a manually actuated member 181 which,when actuated, connects air from the line 54 through check valve topilot 96 of the valve 26. Air on the pilot 96 will close the valve 26,thus exhausting line 98 and line 164. Gravity will then lower the pistonrod 126 and drop the part 131 down out of the mask 132.

The manually operated valve 128 may be used to test or clean the sprayguns 162 when the machine is at rest. Flow control valves 35 and 36control the fiow of oil from the rotomation motor 104 and are used toadjust the speed of the gun carriage 113. Flow control valves 177' and56 are used to adjust the speed with which the guns 162 are tilted atthe end of each stroke. Flow control valves 99 and 99' are used tocontrol the ascent and descent of the piston rod 126 of the cylinder125.

The foregoing specification sets forth the invention in its preferredpractical forms but the structure shown is capable of modificationwithin a range of equivalents without departing from the invention whichis to be understood is broadly novel as is commensurate with the apendedclaims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A machine for painting articles of manufacture comprising a frame,track means on said frame, a carriage on said track means reciprocablethereon, a motor and a paint gun on said carriage, liquid means drivingsaid motor, said motor driving said carriage and the gun thereonsmoothly at a constant velocity, a paint mask mounted on said frame,means to stop said motor and to reverse the movement thereof on saidtrack means, said carriage moving with said gun thereon in proximity tosaid mask to spray paint thereon, air means to actuate said liquid meansand said gun to spray paint on said mask while said carriage is moving,and means to stop the spraying of said gun before the movement of saidcarriage is stopped.

2. An automatic painting machine comprising a frame, an article supporton said frame adapted to support an article, a paint dispensing meanssupported on said frame for reciprocation thereon to deposite paint onsaid article, means to actuate said dispensing means to spray paint onsaid article adapted to be supported on said article support, a liquidmotor on said frame to reciprocate said paint dispensing means andliquid means for applying power directly to said liquid motor, and airmeans controlling the liquid for said liquid motor.

3. An automatic painting machine comprising a hori- Zontally disposedtrack, a gun carriage reciprocably supported on said track, a laterallydisposed crankshaft having a paint gun on its distal end supported onsaid gun carriage, an air actuated cylinder having a piston rod thereinattached to said crankshaft, a reversible hydraulic motor on saidmachine, spaced sprockets, one disposed on said machine at each end ofsaid track, a sprocket on said motor, a chain passing around saidsprockets and attached to said carriage, said motor driving saidsprocket thereon to move said carriage on said track, said carriagemovable from a first end to a second end and return on said track in acycle, a cam driven by said motor, valve means controlling the flow ofliquid to said motor to control the direction of rotation thereof, afirst, a second, a third, and a fourth air control valve on said machineactuated by said cam, said first valve being actuated upon rotation ofsaid motor in a second direction and said second valve actuated uponrotation in a first direction, said second valve actuating means toactuate said air cylinder to rotate said crankshaft to tilt said gun ina reverse direction and actuating means to stop said paint gun fromspraying, said third valve actuating means to reverse said motor at theend of movement of said carriage in a first direction by closing saidvalve means controlling the fioW of liquid, said first valve actuatingmeans stopping the spraying of said gun near the end of travel in asecond direction, said third valve also actuating means starting saidgun to spray at the start of travel of said carriage in a seconddirection, and said fourth valve actuating means stopping said motor atthe end of a cycle of movement of said carriage.

References Cited in the file of this patent UNITED STATES PATENTS1,299,883 Warren Apr. 8, 1919 2,246,502 Bramsen et a1 June 24, 19412,465,174 Schultze Mar. 22, 1949 2,610,605 Paasche Sept. 16, 19522,633,105 Lasater Mar. 31, 1953 2,728,238 Paasche Dec. 27, 19552,728,322 Szczepanski Dec. 27, 1955

